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A place to practice coding with AI!

Reddit · hahayes9 · July 30, 2026
A developer created synthesize.sh, a platform for practicing coding by directing an AI agent to solve algorithm and engineering problems with scoring based on correctness, prompt efficiency, and generation speed. The platform functions like LeetCode but emphasizes effectively using AI, and is currently in free open beta with 10 daily generations per user. The developer plans to add more real-world problems and longer-form engineering challenges.

Detailed Analysis

A solo developer has launched Synthesize (synthesize.sh), a free open-beta platform designed to help engineers practice directing AI agents to solve coding and system-design problems, rather than writing code by hand in the traditional LeetCode mold. Instead of grading raw algorithmic output, the site evaluates three dimensions of AI-assisted work: correctness of the resulting code, token cost efficiency of the prompts and generated solution, and generation time. This reframes the practice-problem format around a skill set that is increasingly central to software engineering roles: prompting and orchestrating an AI coding agent effectively, rather than purely writing algorithms from scratch. The creator has capped usage at 10 runs per day during this early beta and is soliciting bug reports and security feedback directly from the community, characteristic of a scrappy, resource-constrained indie launch.

The significance of this tool lies in its response to a rapidly shifting hiring and skills landscape. As Claude, GPT, and other coding-capable models have become embedded in everyday developer workflows—through products like Claude Code, Cursor, and GitHub Copilot—technical interviews and on-the-job expectations have started to shift away from testing whether a candidate can produce an optimal binary search by hand and toward whether they can effectively delegate, verify, and iterate with an AI agent. Token cost and generation time as scoring metrics reflect real economic and latency constraints that engineering teams now face when deploying agents at scale: a correct solution that burns excessive tokens or takes too long to generate is not actually a good solution in production contexts. By gamifying these constraints, Synthesize aims to train the kind of prompt-engineering and agent-supervision literacy that resembles actual day-to-day AI-assisted development work.

This launch fits into a broader trend of "AI-native" tooling and platforms emerging to fill the gap left by traditional coding education and assessment products, which were built for a pre-agent era. Just as LeetCode became the de facto standard for algorithmic interview prep during the previous decade, there is now visible appetite—reflected in the enthusiasm of the r/ClaudeAI community response—for a parallel standard focused on agent-directed engineering. This mirrors moves by larger players as well: Anthropic itself has been expanding Claude Code's capabilities and documentation around agentic workflows, and various coding platforms have begun introducing "AI pair programming" modes. A grassroots, community-driven tool like Synthesize signals that developers are eager for structured ways to build fluency with agentic coding before employers formalize their own evaluation criteria.

More broadly, the emergence of this kind of practice platform underscores how quickly the definition of "coding skill" is being renegotiated in the LLM era. Where earlier waves of AI coding assistants were treated as autocomplete or boilerplate generators, tools like Claude Code and its competitors are now expected to handle multi-step, agentic problem-solving—planning, executing, and self-correcting across a codebase. Synthesize's metrics-driven approach to teaching people how to work with these agents efficiently, rather than around them, reflects a maturing recognition that prompting and agent supervision are becoming durable, measurable technical competencies. If such platforms gain traction, they could eventually influence how technical interviews are structured industry-wide, much as algorithmic drilling once did, while also generating useful data on how real users interact with coding agents in cost- and latency-sensitive ways—information valuable to both AI labs and enterprise adopters trying to optimize agent deployment.

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